Safety device for locomotives or railway motor vehicles



Nov, 24, l1931. J. T. BUIJGERS SAFETY DEVICE FOR LOCOMOTIVES OR RAILWAY MOTOR VEHICLES sheets-Sheet l Filed Nov. 5o, 1927 w l A Nov. 24, 1931. J. T. BUlJGERs 1,833,516

*SAFETY DEVICE FOR LOCOMOTIVES OR RAILWAY MOTOR VEHICLES 1 Filed Nov. 30, 1927 5 Sheets-Sheet 2 Nv. 24, 1931. J. 1'. BUIJGERS 1,833,516

SAFETY DEVICE FR LOCOMOTIVES OR 'UILWAYl MOTOR VEHICLES Filed Nov. 30, 1927 5 Sheets-Sheet 5 m/ 0% wm@ wd f m@ ,M M. my F w Nov. 24, 1931. J. T. BulJGERs SAFETY DEV-ICE FOR LOCOMOTIVES OR RAILWAY MOTOR VEHICLES Filed NOV. 50, 1927 5 Sheets-Sheet 4 Nov. 24, 1931. J. T. BUIJGERs y 1,833,515

SAFETY DEVICE FOR LOCOMOTIVES OR RAILWAY MOTOR VEHICLES Filed Nov. so, 1927 5 sheets-sheet 5 Patented Nov. 24, 1931 PATENT OFFICE J OHANNIEIS THEODORUS'BUIJ GERS, 0F APELDOORN, NETHERLANDS SAFETY DEVICE non Locoiuorivns R RAILWAY Moron. VEHICLES Application led November 30, 1927, Serial No. 236,727, and inthe Netherlands December 4, 1926.

This invention relates `to an improved safety device for locomotives or railway `motor vehicles for which I filed an application for patent in Holland on December 4, 1926, 'y embracing a Contact mechanism arranged between the rails,'which automatically opcrates a device byy means of a stop lever moved by `said contact device which warns the engine driver` by a signal and applies the brakes The automatic braking however may be prevented or rendered superfluous if the engine driver immediately pays attention to the warning signalemitted.

The invention'has for an object to provide a new and improved braking mechanism.

A further object is to'provi-de an improved braking mechanism automatically operative and of such organization that hazard to the vehicle to which it is attached owing to failure of the device to work will be rendered Ypractically negligible.

The present invention is characterized by the following features:

The period of time which elapses before the brake is applied automatically, a period which'is determined by the time required for the 4operation of the' braking apparatus to 'reach its final braking position, is controlled by a setting device, arranged in such manner that the moment at which automatic braking takes place, canbe varied and determined beforehand as desired. l The train, stopped by means of the safety device, `can only proceed if and wheny the 'safety device has been returned to its original position.

If the stopping device provided on the eny,

' air, so that the brakes cannot be released and the trainso prevented from proceeding.

(c) By the fact that the pressure gauge, i

- normal position.

connected 'to the interior of the hollow stopping device, indicates a lower pressure than that of the pressure gauge connected to the main compressed air reservoir and a vis-I ible or audible signal is thus given.

The improved device assures the greatest possible factor of safety, as a safety device is only reliable when it acts as such in every circumstance and if the action produced on the engine cannot be intentionally eliminated.

My invention has for'one of its objects the particular arrangement of the safety device so that it automatically causes the brake to be applied only after the expiration of a previ- Y ously determined period of time. The en-' rincer after having been warned b the first notes of the signal whistle, will thus be given an opportunity to apply the brakes by hand. According to the invention this object is y realized by providing a variable cross-section of the discharge opening. Through this opening the compressed air escapes fromthe space above the piston, connected to the valve shutting off the brake pipe from the atmos-y pheric air, and the pressure therein closes the valve. This variation of the free cross section is preferably obtained by means of an adjustable valve. In order to provide the highest possible security, this adjustable valve is preferably arranged in such manner that the same may never be completely shut.

A further object of my invention is to prevent the train, after its having been stopped by the safety device from resuming its run before the device has been 'returned to its To this end I provide a distributing or distributor slide, wherebythe valve which shuts olf the brake pipe from the atmosphere is held in the closedposition due, to the pressure exerted by thel compressed air when the said distributor valve is in the central position corresponding to the Working or operative position of the safety device. The result of this is that the brake pipey can only be shut of from atmospheric air when 95 the distributor valve occupies the central or normal position. y

The invention further provides means whereby, in the event of a rupture of the stop lever, the pressure of the compressed'air is x00 In addition to the advantages obtained, the

construction provides the additionaly advantage that inthe? event Ao-bending or sagging of the parts situated under thev engine, the,

' distributing device'willbebrought toi its low'- est pcsition whereby the compressed air. will.V

escape from the space above thevalve, which wspace shuts vo the brake pipe from atmospheric air, the `pressure in which space keeps .theva'lve' inthe closed position.

lFromfthe.constructional point of view, the carryingintopractical'eiiect of the principles mentioned is made possible by the movement ofl astop lever `producing ,the upward move- @ment of acylindrical distributing valve conc Jnected tothe said lever, actingin a cylinder c closedat both ends, and owing tothe movec ment in question 'being assisted by the pressure'v -o the main'compressed air reservoir beginv,ning -to act under the saidv valve due to the upward movement of the cylindrical valve. e,

' One construction embracing the invention iis illustrated by wayof example in the ac- :companying drawings;

lFigure 1 shows a vertical sectionithrough the: ydistributing device and the hollow rod that acts onV thesaiddistributing device operated bythe stop lever.

Y v.Figure-2 shows, inside elevation, the arrangement of the safety device on the en- =01ne.- f v c b l p f l u V v `Figure shows a .preferred-construction of thestop lever. c

i .A Figure shows the same stop leve-returned The devicel shownV in 't inl the main conduit supplying compressed l .,airto the train-pipe, said mainconduit being itselfy connected to they main compressed air through ari-angle of 90.

Figure 1'y is mounted tank 'with the brake valve. The device is .-fdesigned Ytoprovide Jfour-.way connection between the-main compressed air tank, the :train pipe, the atmosphere and the vregist'eringgmechanism.

I i fllV'hile'V inoperative positionl compressed air ffrom .the main tank will beadmitted to z-flow; throughl ,the brake .valve into the train pipe. In'this position the train pipeis shut off. -frm the atmosphere by the movement ovv the pistonffdue to thef pressure exerted ,t #In striking against al contact device pro- 'vidediin a suitable manner on the trackbed,the connections of the four-way device lare reversed.Y In this position the airescapes freely linto the atmosphere and the lcheck valve isfclosed. The outlet opening of the air is'adjustable so that the time can be regulated within which the pressure acting upon the head oi the piston will become suiiciently lowl to cause the pressure under the valve to open same and thereby connect the train pipe with the atmosphere and cause the brakes to be applied. According to the invention the section Yof the outlet opening for the compressed air remains the same after adjustment so that the period of time vrequired beforev the. train 'pipe' opens will makesY` it possiblel to check the engine driven f in order to ascertain whether he has voperated thedevice or whether the brakes were applied automatic.ally,-that is to sayfwithout the cooperation of the engine driver.

Figure 9 shows a modified constructionof the piston-valve. t Figure=10;shows, in `,front elevation, the contact device arrangedubetween the rails when the danger signal isV given.

Figure 11 shows in plan view'the contact device arranged between the-rails so as to cause the signal to be given'. F igureA 12 illustrates Vthe means oradjusting the size of theopening in the piston valve.

The casing lindrical distributing valve 2, `isfconnected by the pipe 3 (Figures 1 and 2) to themain compressed air Areservoir 35. A hollow setting rod 4, moved bythe stopping device (Figures 2 and 3), is secured `tothe piston valve 2 and operates the safety device.

Moreover, on the distributing valve is arrangeda rod' adapted to act on thesteam lwhistle 37 for giving the signal. The valve 6 closes the brake pipe space 7 To the valve 6 is connected a piston 8, acted upon by pressure inY conduit v39 tov keep the valve 6 in a vclosed position.,l The opening 9 provides comrmimication between the piston chamber 25 and the atmosphere.V The said vent or openingmay be made variablefby any ysuitable means, as by a slide 9a, movablel across the opening for closing the sameA more-or less.

By making the vent variable in the manner `,set ortlnthe same maybe adjustedv so as to retard the Vescape of airv from the braking `system' sutliciently. to give the engineer time to manually vopenthe exhaust inthe brake system, and thereby avoid operation of the automatic exhaustion through the herein described apparatus. In addition to the main reservoir the casing 1 is alsolconnected by means of the connecting pipe 10 to a smaller auxiliary reservoir ,36;- The check valve 11 1, in which ismounted the cy-` cuts oif the space communicating with the engineers brake valve rOm'the space above I they piston 8.v .This piston, Aby meansy of the valve 6 that is secured to it, .keeps thebrake pipe space 7 closed. The valve 12,which shuts off the interior 180i the hollow rod 4 yfrornthe innerspace 51'of the distributing valve 2, prevents the-compressed air passing,

in the highest position ofthe piston valve, lfrom the main reservoir through the space 16 and conduit 18 and, by raising valve 14, into i the-space 51.

The valve 14 is ajiat distributing slide valve which is moved by means `of a rod 15 provided with av forli 67 (Figure 7) and is in- '.tended for shutting off the three spacesl16, Yv13 and 51 from, or connecting vthem to, each other. The conduits 17 and 18 establish com- .municati'on between the space 16, situated under the distributing device, and the inner space of the hollow rod 4. A conduit 19, pro- .vided in the valve 12, is intended to admit .compressed air from the main reservoir `through the conduit 17 intothe space'13.

The rod 15 in the construction shown in Figure 9, is replaced by a piston valve 67', which regulates in a simple manner the connection of the chamber 51 to the chambers 13 and 16,

namely by mea-ns of'a recess 68 provided in the inner wall ofthe piston valve 2. The space 16, situated below the distributing -valve 2, can be connected tothe space 13 above 4arranged. on the line between' the rails in the dist-ributin'g'valve by means of a valve 23 which cuts off the connecting conduit constituted by the passages'21 and 22. The

`valve '23Fmay lbe operated by means of a lever 24.

The stop device is operatedV by 'means'of a 'contact device arranged between the rails 28.

The contact device (Figures 10 and 11) is proximity to' somesignal post, for instance lat a distance of about 600'meters therefrom,

and vis operated' simultaneously with the v'semaphore arm of the post.

v'In detail the arrangement comprises a hook 27 arranged between the rails and disposed vertically upwards when the corresponding signal is set to danger. This hookfis connected by means of a transmission rod 69 to the operating mechanism of v'the signal post acting as av control for the order.

movements of hook 27, in such a manner that when the signal gives a clear line indication,

the`hook27 is'turned bythe rod..69 into the horizontal position, against the action ofY a 'tension spring 70 provided on one oit the rails. p' kL f y.

This spring is also intended to pull the f hook 27 into the vertical position in the event of the transmission rod 69 getting out of lAs an additional precaution, the hook may also be. connected to a control device by means of which the signalmanv would be able to with a spring 72.

check in his cabin lthe position of the hook 27 at any moment.

From the hook 27 a number, preferably two, of strong guiding wires or rods-28 Vare carried to the holder 71 which is arranged at*- a certain distance from the hook and between the rails.

In order tosensure that wires, when in use, are kept taut the holder 71 'lhepai'ts are arranged in such a manner that when `the hook 27 is in its vertical position, the wires 26 project above the level of the rails.'` l/Vhen however the hook 27 is turned into the horizontal position, the wiies`vr 26 `will also be turned into a plane situated below the plane of the upper surface of the track. 1

The stopping device (Figures Band 4) coinprises aV stop'lever 47 and two protecting brackets 29 hinged together by means of the pin 48'; ythe brackets 29 are made elastic in operation, by connecting their two upper ends by means ofa spring 30. The hollow rod 4` is provided at its lower end with a pin 34:

to which is secured a flange provided with two pins 33 and 33a. 1

The space 16 (Fig. 1) underneath the piston valve 2 is connected to'space 54 (Fig.

8) through the'opening 52, which'latter ex! tends from the Vspace 16 into the inside of pipe 53 (Fig. 8) leading into space 54. The

' diaphragm 55 is in contact with a pressure plate 57 'formed on the lower end of ay rod 56 provided with a perforating or punching? wheel 58. The lever 62 is pivotally mounted on a piny 61 and is provided with a handle 60. The rod 56 carries a pin 66 by meansof which it can be raised by the lever 62. Connected to lever 62 is a connecting rod 63 on which isf@ mounted a pawl 64 adaptedl to act on the. ratchet teeth 65 of a roller onwhich is wound the band 59 of the automatic recording speed indicator. 4

Thetspace 42 vis connected on the one' hand to the brake pipe 69erl through brake valve 69?) by means of pipe 690 and on the other hand, yby means of the conduit 39, to the outer space of the piston valve 2, the

pipe 3 and to the main reservoir. When the is raised and-the pin 38 is lowered and vicev versa. The spindle 34, shown in Figures 2, 3, 4 and 6, is mounted for pivoting movements upon the trame of the engine. When the brackets 29 come into contact with the sloping part 26 they 4will cause an angular may be provided displacement of spindle l34 whereby rod-,4is moved in an upward direction `by, meansof the pins'33 andr33u.. j

The device is arranged on the locomotive .between 'the connecting pipe 3 ofthe main compressed air. reservoir `and the` brake valve.

f `The operation of theY safetyV device is as vfollowsz- Figure 1 shows ythe piston valve 2 in the "position-of rest. The bracketsV 29 are brought into contact withthe contact devices between the rails 28 as arranged in the event of the `driverI overrunning a danger signal. .e k

The piston valve 2in the `position shown is in 'equilibrium namely, under the action of the pressure from themain reservoir 35 acting onlthe inner -face of the piston valve. In this position, compressed air is free to pass from the main reservoir 35 ,through the outer Vspace 5.0'into lthe spaceabove the valve 8.

' 1 This valve, together' with the valve connected f to it, will be depressed, and consequently the brake pipe space 7 which is directly connected tothe brake pipe-will be maintained vshut oil f v`ronn'r-the opening 40. communicating with the atmospheric air owing' to the pressure of the main reservoir 35. x

' By means of the .check valve 11, controlled by a spring 41, vthe airfrom the main reservoir passes into 'the-space' 42. The spring 41 acts ltomaintain the check valve seatednbut the valve is raised by pressure of .air from lreservoir 35 to permit airV to pass VintoV space l42'..y This space 42 is connected to the brakeV valve so that'the air from t-he main reservoir can: be admitted into'the brakepipe..

" 'Illia-auxiliary reservoir/36 islled with compressed air from the 'main reservoir by Vmeans v'of thel 'pipe 10.

-{Compressed air from the mainreservoir ipass'esfthrough' the passagek in screw plug` 44 andl moves thevalve 12 slightly downwards away from the plug44 in opposition to the -p'ressnreof spring45, so'thatair can enter the space above the valve 12. Theicompressed lair passes from this space to the-conduit 17 through afsmallopening Y19, in the valve 12,

' andfrom the conduit 17 the compressed air passesintothe .interior V13of the hollow rod V 4-which is connected through a flexible pipe Vtween the rails 28.

46 (see Fig. 6) to thev horizontal pin or spindle 34 on which is mounted the-"stop lever 47.

`.The pin 34 and theclever,` 47.are bothvhollow f1-.'55 so that the air may pass V.through them from themain reservoir. Y i

When the engine-overruns a danger signal, one of the elastic brackets-29 comes in con-` tact with the Contact device 26 arranged be- The two brackets 29,

connected together by aspring, act as a shock absorber andare rotatably mounted by means of a pin'48 on thestop bracket proper. Owing to. the bracket 29 ycoming in contact withthecontact device 26, the stop lever 47 -i'sgturned' so that they horizontal spindle 34-is operated and the-,pins v33eandl-33cwhieh are -connectedby means of thev flan'gef49y tothe pin 34* are moved upwards Vor downwards respectively. The e upwardlyl, moved pin` forces'upwardly ,the memberr 32 and the 'rod 4 towhich is secured the pistonva`lve12.v The piston valve 2 is therefore; moved upwardly out ofcits central positionwhen the'engine voverruns a danger signal. Owing to this`v movement the mouth 43 ofthe compressed air pipe 3 is brought under the pistonvalve so that thespace l16is connected to themain reservoir 35..

f Thepiston valve further by the. action of tlierod 4 assisted by .the action of fthe pressure of. the' mainreservoir'in the space 16. In this way the pressure exerted byl the'stopping device; on the rodl 4 will.be.automatically"relieved. The;

rod 5 will4 then be raised withfthexpiston vvalve andthis'rod actuates a steam whistle vto lwarn the engine driver.. Thegengine driver may then allow the'compressed air to escape from: the brake pipe in theusual man-l ner by means of the brake valve and thus stop the train. f

One of the Vadvantages obtained by the present invention is that `no;more air, than is contained in the brake pipe, can escapefx as the main reservoir is shut olf because the piston valve 2, is positioned above opening 43 and cuts oli' the reservoir'35. Ifgi as* soon as the line is` unblocked,V th engine driver wishes to releasethe brakes, heA must again admit compressed air from the main reservoir 35 into the bra-ke pipe. Thisy can be done only if the piston valve is in its-'central position whichis `the position of restof the safety device.` Y To enablethe brakes to be released'k and thetrainfto proceed, thepistonvalve 2 must be brought backft'o the above mentioned'central position by the engine driver lturning the lever 24 upwardly or downwardlyso that; the valve 23 is opened and the space 25 is convnected through "the conduits 21 and 22 to the space 16. The pressurev is equalized inthese ,two spaces and as the piston face vat the .top of the piston valve is greater than at the bot-1 tom owing tothe diilerence in diameter of pipe 4 and thev rod 5, the-piston valve will be moved downwards into the positionl of rest.

openingl 9 communicating Vwiththe atmos-i v 2 `rwillinowbe moved up,`

ne'V driver disre-1H pheric air. Accordingto the size of this outlet opening the pressure of the air escaping from the space 39 and from the auxiliary reservoir 36, connected thereto by the pipe 10,

.drops more or less quickly depending upon the size of the supplemental reservoir and the size of the opening 9. The object of the valve 1-1,V which is closed by the spring 41 and the pressure in space 42 when the pressure in space 32 vvis reduced, is to prevent air from the-'space 42, connected to the 'brake valve, from getting into the space 39 when the `latter is empty thereby counterbalancing the u-pward thrust exerted 'on valve 6. The ca- .pacity vof th'eauxiliaryreservoir 36 is such that a certaintime is required for emptying it, which time is determined bythe size of the openingQ.l Y y When the pressure in [the space 39 has droppedtoa suilicie'nt extent, the pressure in thebrakepipe space V7 will raise the valve 6,

andv *air in the vbrake pipe can then escape through' the Vopening 40 so that the brakes will be applied and the train stopped.

Therefore, since it requires a certainpredetermined timefor the supplemental reservoir 36 to empty, it follows that a certain time elapses between Vthe upward movement of the piston valve 2 and the opening of the valve 6. Therelation of the reservoir 36 and the adju'stment' vof opening 9 tothe casing may also fonce prevail in the vinterior 13 of the `hollow ufupward movement of valve 2, as previously bev such that suiicient time will'elapse between the movement of thevalve 2 and the opening of the valve 6 to give the engine driver an opportunity to apply the brakes by means of the brake valve, after he has been warned bythe steam whistle. i* K' l For releasing the brakes'as soon as the line is clear, the engine driver has to move the piston valve down again, namely by openingthe valve 23 by means ofthe lever24.

When va part .of thel safety device such as forinst'ance the stop lever47 or the spindle` 34 is dama-ged', vatmospheric pressure will' at rod 4, as this interior is connected to the interior of the spindle 34 and the lever 47 and the brakes will be applied and the compressed airftank closed automatically as a result of described. p,

Compressed air will therefore flow from the main reservoir 35 through the openings 43 and-20, through the opening-19 of the valve 12 and the slide valve opening 17 into the interior 13of the .rod 4. Owing to the opening 1 9 being very narrow, and owing to the interior 13 being connected to the atmospheric 'j air a downward force will continue to act on the valve 12 and move it downwardly until the slide valve 14 has closed thev opening 17 p and opened the conduit 18.

" After thevalve 14 has opened the conduit 18 the space -16 will be connected to the main reservoir and the slide valve will be moved upwards.

The outlet opening 43 of the main reservoir opens then into the space 16, so that the main reservoir 1s disconnected from the brake pipe and as the space 39 is connected tothe opening 9 it is put into communication with the atmosphere with the result that the yvalve 6 is raised and the air escapes from the brake v 5 Y As the valve 14 is not secured to the valve I pipe.

in the usual manner. Only after the device has been properly repaired will the train be able to proceed.

Theoperation of the indicator device is as follows d By means of the indicator device provided on the safety device, a record will be made on the band of an automatically recording speed indicator or speedometer provided on the engine whenever the safety device is operated or whenever the stop lever is brought fromthe operative into an inoperative position. A device is provided on the indicator device by means of which the engine drivel-himself can make such a record on the band. In this way the locomotive driver is in a position to indicate on the band that he observed that the device could be operated and that he paidv attention to the signal.

Next to the opening 52 (Figure 1) of the pipe 53 (Figure 8) under the piston valve 2 is arranged the space 16 `(Figurefl) which is connected to the -space 54 under the diaphragm 55.` Onsaid diaphragm `rests a pres` sure plate 57 provided at the lowe-r'end of a rod 56. The rod 56 carries'a perforating or punching wheel 58 or a like member .adapted to act on the band59. ofthe automatic recording speed-indicator. 1f, owing to the operation of .the safety device, the pressure.

of the main yreservoir is transmitted to the space 16' the said pressure will be transmitted f through the opening 52 and pipe 53 into the The diaspace 54 under the diaphragm 55. phragm will thus be raised. The pressure plate 57, with the rod 56, will be raised and by means of the'perforating wheel 58 a regular record' will be produced on the band 59of the automatic recording speedometer.

When the engine driver operates the handle 60 the lever will be turned about the fulcrum 61. The rod 56 is moved upwardly by.

" move; to kposition'jfor effecting braking action meene ot-Piri .66 and thererforetinefwheel 58 is 'pressed against the band 59 and a -rec-` ord thus being produced onY the band. The band 59 Vis movedslightly by means of the vconnecting rodv 63, ratchet gear `andjteeth Whenthe recording device lis operated as avresult of automatic operation` ofthe-brakes the :rod 516 Will'Y press lthe perforating Wheel ,'58 against the band and on the latter will 4-iial operation of the recorderathe band is moved .while the vrp erforating .wheel .5,8 Ais in contact therewith thus rotating-Athefkywheel and-producing an irregularrecord; The automatic operationresults inY one ortwo per- ;forationsof'the' bandaand the manual operation results fin-a number of perforations iny the form of a track. :Because of fthe differs ences between vtliejftvvo records ony the bandV itis easyy to @determine whether or vnot the engineer vresllionded@to the signalfto apply the brakes and Operated the recorder inthe interval Vbefore,automatic :brake application Wouldtake-place, x @j Y, 1 f Y Villillatlclaim is:,-, ,l Y l. In a: pneumatic braking systemfinclud# ing a compressed air reservoir 'and a brake v pipe connect-ed by'a piston chamber; a distributor piston valve movable to and lfrom position insaid chamber lfor effecting braking ac- .ition in ,the system, said piston valve having a chamber therein, a tubular control rodi com-l` municating with the chamber of the piston f valve, a passage through: thepiston 'valve connectingftheinterior of the control "rod ,Swith Vthechamber, and a' yieldably seated valve inA saidpassage controlling flow kof :fluid from ,the systemf into'jtlie control rod,fan`d means; operablev when'said yieldably sea-ted valve isr open for causing the 'piston valve vto on the system'. f v

- 2;, In alv pneumatic braking system'l includ,- inga'brakepipe and a compressed air reservoijr Qommunicating withV aA chambered caszing, said casing having a venttol the .atmosphere toward one' end; la `distributor,piston within the casing having a recess formed* therein .normally positioned; Yto, yafford communeetionbetween the. reservonand brake.

- Q51 pipe, and, te eutfpoit ACorrrlimin eatioh between .y

the reservoir and' pipe li-ronif said vent, said' piston being adapted- When moved from its normal position -to provide vcommunicationbetween the brake pipe and said vent,

a normally closed `-hollow member commu` nicating withy the frecessjin the piston, a yieldablyV seated vv"valve Controlling flow ,of

iiuidrinto said' membervirom theV said Yre-` cess, saidinember havingan opening leading to the chamber .beneath the piston, means normally closing the opening, said means being adapted to open said opening under-influence of pneumatic pressure Vfrom said chamber when the yieldably seated valve is open. Y

f8.; A pneumatic braking 'system VIincluding a brake pipe, a compressed air reservoir, and a casing having a chamber provided 'with a vent to the atmosphere adjacent oneendandr having communicating passages both with saidbrake -pipeand said reservoir, a distributor piston movable within said chamber,fsaid piston being normally positioned to providecommunication between 'Said Passages and so as to cut off communicationfbetween.the passages and the vent, said vdistributorp-iston being vformed `with-heads Vat-oppositeends defining a recess providing communicationv between ,the pipe and reservoir whenthe piston is innormal position and'tlirougli whichk thepipe communicatesiwiththe vent when the vpiston is displaced from` normal position, the communication. of thefpassage from the reservoir withp/ the 'chamber being so posi-` tioned as to be below the piston whenthe pipe is incommunication with the vent said pistonhaving a chamber formed thereinwhich is in communicationv with there/cess, between the heads, a hollow member extending from thepiston and normally closed against atmospheric air, saidmember communicating .with

said recess,avieldablly7 seatedl valve separat-r ing therecess fromrthe interiorof the said member, a vent said member within vthe chamber and beneath the piston, means nor@ mally `closing the ventand adaptedto Open the same under influence of movement ',ofsaid l yieldablyseate'd valve. v A

4. fAn automatic safety device lfor railways, comprising in combination, a main com; pressed' airtank, a brake valve, al main conduit for the compressed air connecting ,said -brake valve to said `air tank, a, check valve mounted in said main Vconduit and a fourway connecting valve mounted uponsaid Vmain conduit between the checkvalve fand the Amain tank, acanalV to vthe atmospheric air provided in the' connecting housing, a connection between said valve and the main con-.

duit, a connection therefrom to the canal', a registering mechanism, a pipe leading to said registering `mechanism and aconnection be-k tween saidpipe andtheatrriosphere and the main tank. i

5f automatie-y Safety devceior, railways: eoinprislngli-n combination, a

compressed air tank, a brake valve, a main conduit for the compressed air connecting said ybrake val-ve to said air tank, a Cheek valve mounted in said main conduit and a four-way connecting valve mounted upon said main conduit between the cheek valve and the main tank, an adjustable outlet into the free atmosphere provided in said connecting valve, a device for shutting off the train pipe from the atmosphere under the influence of the pressure in the main conduit between the cheek valve and the four-way connection, and an auxiliary reservoir connected to the main conduit between the cheek valve and the four-way valve connection.

In testimony whereof I have aixed my sig nature.

JOHANNES THEODORUS BUIJGERS. 

